Fix objc_storeStrong pattern matching to catch a potential use of the

old value after the store but before it is released.
This fixes rdar:/11116986.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156442 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 76 insertions, 0 deletions

diff --git a/test/Transforms/ObjCARC/contract-storestrong.ll b/test/Transforms/ObjCARC/contract-storestrong.ll
index 4ff0596fbb..376120cf8b 100644
--- a/test/Transforms/ObjCARC/contract-storestrong.ll
+++ b/test/Transforms/ObjCARC/contract-storestrong.ll
@@ -4,6 +4,7 @@ target datalayout = "e-p:64:64:64"
 
 declare i8* @objc_retain(i8*)
 declare void @objc_release(i8*)
+declare void @use_pointer(i8*)
 
 @x = external global i8*
 
@@ -57,3 +58,78 @@ entry:
   tail call void @objc_release(i8* %tmp) nounwind
   ret void
 }
+
+; Don't do this if there's a use of the old pointer vlaue between the store
+; and the release.
+
+; CHECK:      define void @test3(i8* %newValue) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+; CHECK-NEXT:   %x1 = load i8** @x, align 8
+; CHECK-NEXT:   store i8* %x0, i8** @x, align 8
+; CHECK-NEXT:   tail call void @use_pointer(i8* %x1), !clang.arc.no_objc_arc_exceptions !0
+; CHECK-NEXT:   tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+define void @test3(i8* %newValue) {
+entry:
+  %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+  %x1 = load i8** @x, align 8
+  store i8* %newValue, i8** @x, align 8
+  tail call void @use_pointer(i8* %x1), !clang.arc.no_objc_arc_exceptions !0
+  tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Like test3, but with an icmp use instead of a call, for good measure.
+
+; CHECK:      define i1 @test4(i8* %newValue, i8* %foo) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+; CHECK-NEXT:   %x1 = load i8** @x, align 8
+; CHECK-NEXT:   store i8* %x0, i8** @x, align 8
+; CHECK-NEXT:   %t = icmp eq i8* %x1, %foo
+; CHECK-NEXT:   tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+; CHECK-NEXT:   ret i1 %t
+; CHECK-NEXT: }
+define i1 @test4(i8* %newValue, i8* %foo) {
+entry:
+  %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+  %x1 = load i8** @x, align 8
+  store i8* %newValue, i8** @x, align 8
+  %t = icmp eq i8* %x1, %foo
+  tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+  ret i1 %t
+}
+
+; Do form an objc_storeStrong here, because the use is before the store.
+
+; CHECK: define i1 @test5(i8* %newValue, i8* %foo) {
+; CHECK: %t = icmp eq i8* %x1, %foo
+; CHECK: tail call void @objc_storeStrong(i8** @x, i8* %newValue) nounwind
+define i1 @test5(i8* %newValue, i8* %foo) {
+entry:
+  %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+  %x1 = load i8** @x, align 8
+  %t = icmp eq i8* %x1, %foo
+  store i8* %newValue, i8** @x, align 8
+  tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+  ret i1 %t
+}
+
+; Like test5, but the release is before the store.
+
+; CHECK: define i1 @test6(i8* %newValue, i8* %foo) {
+; CHECK: %t = icmp eq i8* %x1, %foo
+; CHECK: tail call void @objc_storeStrong(i8** @x, i8* %newValue) nounwind
+define i1 @test6(i8* %newValue, i8* %foo) {
+entry:
+  %x0 = tail call i8* @objc_retain(i8* %newValue) nounwind
+  %x1 = load i8** @x, align 8
+  tail call void @objc_release(i8* %x1) nounwind, !clang.imprecise_release !0
+  %t = icmp eq i8* %x1, %foo
+  store i8* %newValue, i8** @x, align 8
+  ret i1 %t
+}
+
+!0 = metadata !{}